#include "receiver_harness.hh"
#include "util.hh"
#include "wrapping_integers.hh"

#include <cstdint>
#include <cstdlib>
#include <exception>
#include <iostream>
#include <optional>
#include <random>
#include <stdexcept>
#include <string>

using namespace std;

int main() {
  try {
    auto rd = get_random_generator();

    // An in-window, but later segment
    {
      uint32_t isn = uniform_int_distribution<uint32_t>{0, UINT32_MAX}(rd);
      TCPReceiverTestHarness test{2358};
      test.execute(SegmentArrives{}.with_syn().with_seqno(isn).with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(SegmentArrives{}.with_seqno(isn + 10).with_data("abcd").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(ExpectBytes{""});
      test.execute(ExpectUnassembledBytes{4});
      test.execute(ExpectTotalAssembledBytes{0});
    }

    // An in-window, but later segment, then the hole is filled
    {
      uint32_t isn = uniform_int_distribution<uint32_t>{0, UINT32_MAX}(rd);
      TCPReceiverTestHarness test{2358};
      test.execute(SegmentArrives{}.with_syn().with_seqno(isn).with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(SegmentArrives{}.with_seqno(isn + 5).with_data("efgh").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(ExpectBytes{""});
      test.execute(ExpectUnassembledBytes{4});
      test.execute(ExpectTotalAssembledBytes{0});
      test.execute(SegmentArrives{}.with_seqno(isn + 1).with_data("abcd").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 9}});
      test.execute(ExpectBytes{"abcdefgh"});
      test.execute(ExpectUnassembledBytes{0});
      test.execute(ExpectTotalAssembledBytes{8});
    }

    // An in-window, but later segment, then the hole is filled, bit by bit
    {
      uint32_t isn = uniform_int_distribution<uint32_t>{0, UINT32_MAX}(rd);
      TCPReceiverTestHarness test{2358};
      test.execute(SegmentArrives{}.with_syn().with_seqno(isn).with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(SegmentArrives{}.with_seqno(isn + 5).with_data("efgh").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(ExpectBytes{""});
      test.execute(ExpectUnassembledBytes{4});
      test.execute(ExpectTotalAssembledBytes{0});
      test.execute(SegmentArrives{}.with_seqno(isn + 1).with_data("ab").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 3}});
      test.execute(ExpectBytes{"ab"});
      test.execute(ExpectUnassembledBytes{4});
      test.execute(ExpectTotalAssembledBytes{2});
      test.execute(SegmentArrives{}.with_seqno(isn + 3).with_data("cd").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 9}});
      test.execute(ExpectBytes{"cdefgh"});
      test.execute(ExpectUnassembledBytes{0});
      test.execute(ExpectTotalAssembledBytes{8});
    }

    // Many gaps, then filled bit by bit.
    {
      uint32_t isn = uniform_int_distribution<uint32_t>{0, UINT32_MAX}(rd);
      TCPReceiverTestHarness test{2358};
      test.execute(SegmentArrives{}.with_syn().with_seqno(isn).with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(SegmentArrives{}.with_seqno(isn + 5).with_data("e").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(ExpectBytes{""});
      test.execute(ExpectUnassembledBytes{1});
      test.execute(ExpectTotalAssembledBytes{0});
      test.execute(SegmentArrives{}.with_seqno(isn + 7).with_data("g").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(ExpectBytes{""});
      test.execute(ExpectUnassembledBytes{2});
      test.execute(ExpectTotalAssembledBytes{0});
      test.execute(SegmentArrives{}.with_seqno(isn + 3).with_data("c").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(ExpectBytes{""});
      test.execute(ExpectUnassembledBytes{3});
      test.execute(ExpectTotalAssembledBytes{0});
      test.execute(SegmentArrives{}.with_seqno(isn + 1).with_data("ab").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 4}});
      test.execute(ExpectBytes{"abc"});
      test.execute(ExpectUnassembledBytes{2});
      test.execute(ExpectTotalAssembledBytes{3});
      test.execute(SegmentArrives{}.with_seqno(isn + 6).with_data("f").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectUnassembledBytes{3});
      test.execute(ExpectTotalAssembledBytes{3});
      test.execute(ExpectBytes{""});
      test.execute(SegmentArrives{}.with_seqno(isn + 4).with_data("d").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectUnassembledBytes{0});
      test.execute(ExpectTotalAssembledBytes{7});
      test.execute(ExpectBytes{"defg"});
    }

    // Many gaps, then subsumed
    {
      uint32_t isn = uniform_int_distribution<uint32_t>{0, UINT32_MAX}(rd);
      TCPReceiverTestHarness test{2358};
      test.execute(SegmentArrives{}.with_syn().with_seqno(isn).with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(SegmentArrives{}.with_seqno(isn + 5).with_data("e").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(ExpectBytes{""});
      test.execute(ExpectUnassembledBytes{1});
      test.execute(ExpectTotalAssembledBytes{0});
      test.execute(SegmentArrives{}.with_seqno(isn + 7).with_data("g").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(ExpectBytes{""});
      test.execute(ExpectUnassembledBytes{2});
      test.execute(ExpectTotalAssembledBytes{0});
      test.execute(SegmentArrives{}.with_seqno(isn + 3).with_data("c").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 1}});
      test.execute(ExpectBytes{""});
      test.execute(ExpectUnassembledBytes{3});
      test.execute(ExpectTotalAssembledBytes{0});
      test.execute(SegmentArrives{}.with_seqno(isn + 1).with_data("abcdefgh").with_result(SegmentArrives::Result::OK));
      test.execute(ExpectAckno{WrappingInt32{isn + 9}});
      test.execute(ExpectBytes{"abcdefgh"});
      test.execute(ExpectUnassembledBytes{0});
      test.execute(ExpectTotalAssembledBytes{8});
    }

  } catch (const exception &e) {
    cerr << e.what() << endl;
    return 1;
  }

  return EXIT_SUCCESS;
}
